Sigma lenses and Pentax body marriage

pop4 · 05-13-2011, 08:04 PM

Originally posted by marinb

I am not used with Nikon and Canon, but I am almost sure that they don't have that problems. Am I wrong?

You're quite wrong, and just be very glad you're not shooting with Canon bodies and Sigma lenses; I'm over on the Canon Photography On The Net forums quite a bit, and there are many instances of Sigma focusing issues on Canon bodies. On the other hand, it's quite interesting, but I don't seem to read as much about AF issues with Sigma lenses and Nikon bodies.

And just for your information, I've got about 7 Sigma lenses what I've used with the Pentax K10D, K-7 and now the K-5, and I haven't had the issues you're having now. Some combinations did need a bit of + or - AF adjust, but I've been getting sharp and in-focus images, nothing like what you're getting. So it is possible to get sharp images with a Pentax body and Sigma lens; the issue is why aren't you getting sharp images, and how to fix that

marinb · 05-14-2011, 03:26 AM

Hello everybody. So, I put a AF test chart in front of the camera. I mounted my 70-200mm lens an started testing. The final conclusion is that the camera needs -10 (even more, but that is the maximum) AF adjustment (Apply One) for this lens. Then I mounted the second lens 24-70mm. The field Apply One was set to 0 (zero) by default. OK. It means that the camera did the difference between 70-200mm and 24-70mm. OK. The second lens also needed -10 (even more, but that is the maximum). The third lens was 50mm f1.4. Well, in this case I think the camera made no difference between 24-70mm and 50mm. Anyway, even 50mm lens needed the same amount -10. The difference is striking. Really. Well, guys, thank You for every advise. It was a real help. I think the case is closed. Good luck to everybody. I hope I will be able to help some of You in the future.

marinb · 05-14-2011, 03:28 AM

By the way, these are some close-up shots. The child was moving all the time. I really hope that the outdoor shots, from a bigger distance will have the same positive results.

Pablom · 05-14-2011, 03:51 AM

congrats for solving your problem.

Lovely child photo

dickymastelero · 05-14-2011, 04:53 AM

Yes, you finally got it tuned to the right adjustments. All of my Sigma Lenses are all set to -10, want to tell you this but its better you get the experience to set it up. Happy shooting.

rawr · 05-15-2011, 04:42 PM

Take the filters off your lenses too.

05-14-2011, 03:26 AM	#17
marinb Forum Member Join Date: Jan 2010 Location: Chisinau Photos: Gallery Posts: 60 Original Poster	test Hello everybody. So, I put a AF test chart in front of the camera. I mounted my 70-200mm lens an started testing. The final conclusion is that the camera needs -10 (even more, but that is the maximum) AF adjustment (Apply One) for this lens. Then I mounted the second lens 24-70mm. The field Apply One was set to 0 (zero) by default. OK. It means that the camera did the difference between 70-200mm and 24-70mm. OK. The second lens also needed -10 (even more, but that is the maximum). The third lens was 50mm f1.4. Well, in this case I think the camera made no difference between 24-70mm and 50mm. Anyway, even 50mm lens needed the same amount -10. The difference is striking. Really. Well, guys, thank You for every advise. It was a real help. I think the case is closed. Good luck to everybody. I hope I will be able to help some of You in the future. Attached Images

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05-13-2011, 08:04 PM	#16
pop4 Veteran Member Join Date: Aug 2007 Location: YMML Photos: Gallery Posts: 1,879	Originally posted by marinb I am not used with Nikon and Canon, but I am almost sure that they don't have that problems. Am I wrong? You're quite wrong, and just be very glad you're not shooting with Canon bodies and Sigma lenses; I'm over on the Canon Photography On The Net forums quite a bit, and there are many instances of Sigma focusing issues on Canon bodies. On the other hand, it's quite interesting, but I don't seem to read as much about AF issues with Sigma lenses and Nikon bodies. And just for your information, I've got about 7 Sigma lenses what I've used with the Pentax K10D, K-7 and now the K-5, and I haven't had the issues you're having now. Some combinations did need a bit of + or - AF adjust, but I've been getting sharp and in-focus images, nothing like what you're getting. So it is possible to get sharp images with a Pentax body and Sigma lens; the issue is why aren't you getting sharp images, and how to fix that

05-14-2011, 03:28 AM	#18
marinb Forum Member Join Date: Jan 2010 Location: Chisinau Photos: Gallery Posts: 60 Original Poster	By the way, these are some close-up shots. The child was moving all the time. I really hope that the outdoor shots, from a bigger distance will have the same positive results.

05-14-2011, 03:51 AM	#19
Pablom Veteran Member Join Date: Feb 2010 Location: Usa Posts: 1,940	congrats for solving your problem. Lovely child photo

05-14-2011, 04:53 AM	#20
dickymastelero New Member Join Date: Mar 2011 Location: Edmonton, Alberta CANADA Photos: Albums Posts: 16	Yes, you finally got it tuned to the right adjustments. All of my Sigma Lenses are all set to -10, want to tell you this but its better you get the experience to set it up. Happy shooting.

05-15-2011, 04:42 PM	#21
rawr Veteran Member Join Date: Jun 2009 Posts: 11,913	Take the filters off your lenses too.

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